1. Field of the Invention:
This invention relates in general to earth boring bits, especially to those with replaceable fluid nozzles.
2. Background Information:
Earth boring bits used for drilling deep wells for petroleum and minerals have wear resistant nozzles to direct fluid against the bottom of the borehole. Usually, the nozzles are replaceable to accommodate the "hydraulic program" for each particular drilling rig and expected depth interval.
Nozzle designs include those retained with snap rings, nails and threads in a variety of configurations. Nozzles retained with threads sometimes have a hexagonal socket on the lower end to receive an "Allen" type wrench for insertion and removal of the nozzle. Some nozzles have noncircular throats to accomplish such purposes as diffusion of the exit stream and an irregular flow passage in an attempt to prevent blockage by solids in the drilling fluid. And yet, there is need for an improved compact nozzle configuration or design in all types of bits, including the "diamond" bit where the placement of natural or artificial diamonds and the fluid nozzles may be especially restricted due to severe space limitations.